The "Sword Of Damocles" is put into place." I have given Black's move a question mark because computer analysis shows that 1)... bf2+ wins for black! The move given was the one actually played in the game, some time before the invention of chess computers. The idea of Black's "Bad Move" was to "Attack White's Queen" and "Force" it off the Diagonal." The Queen at f6 is a "Gun" to the head of the King, the Queen "Controlling The Long Diagonal," is a very important "Positional Advantage."